Quick make and break mechanism for electric switches



March 28, 1950 ROWE 2,501,742 quxcx MAKE AND BREAK MECHANISM FOR ELECTRIC SWITCHES Filed Aug. 24, 1948 Fi j I 419,4 Inventor":

r R d N R V U I, H I H I), I 7 agmon OWGB gas 37 35 30:51 $2 5 8; V His Att fr-neg- Patented Mar. 28, 1950 QUICK MAKE AND BREAK MECHANISM FOR ELECTRIC SWITCHES Raymond N. Rowe, Plalnville, Conn., .assignorto The Trumbull Electric Manufacturing Company, Plainville, Conn, a corporation of Connecticut Application August 24, 1948, Serial No. 45,832

8 Claims.

The invention relates particularly to throwing mechanism which is manually operable and applicable to various types of contact mechanism.

The main object is to provide a simple and reliable snap action mechanism requiring but few and simple parts.

Other objects are to provide a snap action mechanism which can be readily assembled and easily inspected and which is cheaper to make.

Another object is to provide a snap acting mechanism with a dead center position so unstable that it is impossible as a practical matter to stop the mechanism on the dead center position.

Another object is to provide a snap acting mechanism which is extremely compact so as to be suitable for use in a box behind the switch units which it operates.

The form shown is especially adapted to use with front operated switches of the enclosed type but the invention is not so limited.

Fig. 1' is a front view of an enclosed type of switch embodying my invention showing the cover broken away and the switch parts in the off position.

Fig. 2 is a side view and partial section of the same.

Fig. 3 is a view of the back of the switch showing the quick make and quick break mechanism in the off position.

Fig. 4 is a view similar to Fig. 3 but showing the parts in the on position. i

I Fig. 5 is a fragmentary detail edge and sectional view showing the mounting of the actuating hub and shaft.

As the invention relates to the quick make and quick break mechanism the other parts need only be described briefly.

The base plate I has flanges 8 extending backward and terminating at the ends in feet 9 adapted to be secured to a support I0 in the bottom of the box I I having a cover I 2.

Switch units such as l4, M are suitably mounted on the front of the base plate being secured by nuts I5, l6 and provided with circuit terminals l1 and IB. Such a. unit is shown and claimed in my application Ser. No. 708,375 filed Nov. '7, 1946, now Patent 2,468,235. An insulating plate I is interposed between the plate I and the switch units.

These switch units are actuated by ,a crank shaft I9 hinged at in the side flange 8. The shaft extends in front of the base plate and beneath the switch units and is connected in any 3 suitable manner with suitable movable switch members 2| which coact with contacts 22 and 23 for instance as shown in my said Patent The throwing lever arm 24 is pivoted at 25 and has a forked tip 26 bent around one side of the 2 base plate through a slot 21 to connect with one arm of the crank shaft I9. A stop 24' may be provided for arm 24.

An oscillatable hub 30 is pivoted 'on a central bearing pin 3| beneath the base plate I and has an offset 32. The actuating shaft 33 passes through an arcuate slot 34 in the base plate and through the hub and is secured to the hub 33 and the oflset 32 so that the hub can be turned by the shaft 33 through an angle limited by the length of the slot 34. The shaft has an external handle 33' of suitable construction.

The hub plate has an offset 35 with a slot 36 to receive a bearing roller or pin 31 on the end of the rod 38 which carries the spring 39. This spring is compressed between the head of the rod 38 and the lug 40 pivoted to the lever arm 24 so as to tend to rotate the hub plate clockwise as viewed in Fig. 3 and counterclockwise in Fig. 4 about 90.

A rocker M is also pivoted on pin 3| and has a slot 42 through which the shaft 33 passes. The spring pressure therefor biases the hub plate, the shaft 33 and the rocker M to the position of Fig. 3 where the shoulder 43 abuts against the stop It so that the rocker may have a free turning angle of about 60. The link 45 passes to one side of the hub and connects the rocker arm at 48 with the lever arm 24 at 41.

To move the parts from the "013 position of Fig. 3 to the on position of Fig. 4 it is merely necessary to turn the hub plate 30 anti-clockwise as viewed in Fig. 3 by means of the shaft 33. As soon as the bearing 31 passes the line of centers (3l-4Ii), the bearing 3'! will slide from the right hand end of slot 36 to the left hand end and thus suddenly reverse the action of the spring and throw the parts to the on position of Fig. 4 when the arm of the rocker M abuts against the stop It. This construction makes it practically impossible to stop the mechanism in its dead center position.

To turn from the on to the off position the action is reversed.

To further ensure avoidance of a dead center action, I may provide an inclined shoulder 36' near each end of the slot 36 so that when the hub member 34 is being turned the roller bearing 31 will be held back until the center line has been passed whereupon the bearing will slip over the shoulder'and suddenly pass to the opposite end of slot 36 and reverse the action of the spring.

It will thus be seen that the parts are simple and of such a form as to be easily made and as small as practical considering the forces they must transmit.

I claim:

1. In a quick make and break switch, a base plate, a hub mounted on said plate and having two offset arms and having a limited rotative movement on said plate, an actuating shaft passing through said plate and connected to said hub and to one of said offset arms, a rocker pivoted coaxially with said hub and having a lost motion connection with said hub and shaft, 9. throwing arm hinged to said plate at one side of said hub, a link connecting said rocker to said arm, a rod and spring interposed between the other arm of said hub and said throwing arm. and stops for limiting the turning of the rocker and a switch actuating member held in its "off position by the pressure of said spring and said throwing arm.

2. In a quick make and break switch, a base plate, a hub mounted on said plate and having two offset arms and having a limited rotative movement on said plate, an actuating shaft passing through said plate and connected to said hub and to one of said offset arms, the other arm being slotted, a rocker pivoted coaxially with said hub and having a lost motion connection with said hub and shaft, a throwing arm hinged to said plate at one side of said hub, a link connecting said rocker to said arm, a rod and spring interposed between the slotted arm of said hub and said throwing arm, the hub and its slotted arm being turnable on its axis so as to carry its slotted arm from one side of the center line connecting the guide of the throwing arm and the axis of the hub to the other side of said center line and a switch actuating member held in its off position by the pressure of said spring and said throwing arm.

3. In a snap action switch a base plate for supporting switch units, a hub mounted beneath the base plate and having two oil'set arms extending from its periphery with the radii of the arms spread apart, an actuating shaft passing through a slot in the base plate and connected to one of said arms, the other arm having a slot'transverse to the radius of said latter arm, a throwing rod having a bearing at one end slidable in said slot, a throwing arm hinged to the base plate at one side of said hub and slidably supporting the other end of said rod, a rocker hinged coaxiallv with said hub and having at one end a lost motion connection with said shaft and a link hinged to the other end of said rocker and hinged to said throwing arm and means for limiting the swing of said arm and a switch actuatin member above said base plate actuated by said throwing arm.

4. In a snap action switch a base plate for supporting switch units, a hub mounted beneath the base plate and having two ofl'set arms extending from its periphery with the radii of the arms spread apart, an actuating shaft passing through a slot in the base plate and connected to one of said arms, the other arm having a slot transverse to the radius of said latter arm, a throwin: rod having a bearing at one end slidable in said slot. a throwing arm hinged to the base plate at one side of said hub and slidably supporting the other end of said rod, a rocker hinged coaxially with said hub and movable back and forth approximately 90 and having at one end a lost motion connection with said hub, a link hinged the base plate and having two offset arms extending from its periphery with the radii oi the arms Q spread apart, one arm having a return bend. an actuating shaft passing through a slot in the base plate and connected to said hub and to the return bend of one of said arms, a throwing rod having a bearing with a lost motion connection to the other arm, a throwing arm hinged to the base plate at one side of said hub and slidably supporting the other end of said rod, a rocker hinged coaxially with said hub and having at one end a lost motion connection with said shaft between said hub and said return bend, a link hinged to the other end of said rocker and hinged to said throwing arm and stops for limiting the swing of said rocker and a switch actuating member above said base plate actuated by said throwing arm.

6. In a snap action switch a base plate for supporting switch units, a hub mounted beneath the base plate and having two arms extending from its periphery with the radii of the anus spread apart about an actuating shaft passing through the base plate and connected to one of said arms, the other arm having a slot transverse to the radius of said latter arm, a throwing rod having a hearing at one end slidable in said slot, a throwing arm hinged to the base plate at one side of said hub and slidably supporting the other end of said rod, a rocker hinged ccaxially with said hub and having at one end a lost motion connection with said hub, a link hinged to the other end of said rocker and hinged to said throwing arm and stops for limiting the swing of said rocker and a switch actuating member above said base plate actuated by said throwing arm.

7. In a quick make and break switch, a base plate, a hub mounted on said plate and having two offset arms and having a limited rotative movement on said plate, an actuating shaft passing through said plate and connected to said hub, a rocker pivoted coaxially with said hub and having a lost motion connection with said shaft.

a throwing arm hinged to said plate at one side of said hub, a link connecting said rocker to said arm and a rod and spring interposed between the other arm of said hub and said am and having a lost motion connection with said arm and a switch actuating member held in its off position by the pressure of said spring and said throwing arm.

8. In a quick make and break switch, a manually oscillatable hub having an arm pro- Jecting radially thereof, a pivoted throwing arm, a spring-pressed rod connecting said throwing arm and the arm of said hub, said latter arm having a slot extending transversely of the radius of said arm and having two inclined projections along the edge of said slot spaced from the ends of said slot and said rod having a roller in said slot coacting with one of said shoulders as the hub is turned from the on" to the "oil?" position and from the oil' to the "on position.

RAYMOND N. ROWE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,539,104 Amos May 26, 1925 1,588,359 Hammann June 8, 1926 1,863,523 Hammerly June 14, 1932 2,318,227 Jackson May 4, 1943 

